12 day road trip suggestions

I'm looking for some advice. A group of 4 will be doing a 12 day trip from red lodge, MT to oregon/northern california at the end of sept. We have two decent riders, and two novices. Looking for trail suggestions. I haven't been further west than Idaho, and our itinerary is flexible. We'll be camping, and would love to hear some suggestions on where we should check out...any can't miss spots biking/hiking/or otherwise? Thanks guys!